Layout: domain model SVG ignores stored association anchors; no crossing-minimising mode; auto-layout lacks early-stop shape #1692

What happens

Three layout gaps seen when generated models are reviewed visually:

1. Domain model SVG ignores stored anchors. mxcli describe --format svg domainmodel <Module> draws every association centre to centre. The stored association anchors are ignored (tested with extreme anchor values), so the SVG cannot be used to verify "corner to corner" lines.
2. No layout mode that minimises crossings for the domain model (mxcli layout), and no crossing check from the same geometry.
3. Microflow auto-layout produces merge-before-end shapes. A guard with an empty ELSE plus a merge renders with crossing lines and two merge diamonds before the end event. Wanted for the unhappy path: it leaves the main line straight down to its own end event (optionally one activity before it), without a merge; happy paths may merge into one end event.

Expected

1. The SVG uses the stored anchors.
2. mxcli layout gets a mode that minimises crossings (and optionally snaps to a grid).
3. Auto-layout places an unhappy branch straight down to its own end event.

Related: #1672, #724 (beautify), #1154 (closed).

Environment

mxcli 0.28.0, Studio Pro 11.12.4, Windows 11. Found by the AppGen tooling (Ciphix) on a test app.